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Biodiversity net gain
What is biodiversity net gain?
Biodiversity net gain (BNG) is an approach to development and/or land management that aims to leave the natural environment in a measurably better state than it was beforehand. The word 'biodiversity' comes from the term 'biological diversity'.
Why is it important?
The Environment Act 2021 introduced the duty to deliver minimum 10% BNG through planning decisions; this requirement was enacted on 12 February 2024. To be clear, this is a mandatory requirement – applicable developments have to demonstrate 10% net gain otherwise we will be unable to approve them. It is not something we can assess as part of the planning balance.
The National Planning Policy Framework notes that improving biodiversity is one of the objectives to deliver sustainable development; Paragraph 180 refers directly to providing net gains for biodiversity.
The adopted Swindon Local Plan contains Policy EN4 (Biodiversity and Geodiversity), which requires development to avoid negative impacts and for applicable developments also to provide biodiversity net gain.
Does it affect all planning applications?
The requirement to demonstrate BNG applies to all applications apart from small sites, householder applications, and some custom/self-build developments. The requirement for delivering BNG on small sites will be introduced on 2 April 2024.
Small sites are defined as proposing between one and nine dwellings on a site of less than one hectare, or – where the number of dwellings proposed is not yet known – a site area of less than 0.5 hectares. For non-residential development, a small site is one where the floorspace created is less than 1,000 square metres OR where the site area is less than one hectare.
What do applicants have to do?
As a result of the mandatory need for delivering BNG applicants will need to provide sufficient information with their planning applications to allow the council to make an informed judgement on this issue.
Please note: If you do not do this, we will be unable to validate the application.
Developers need to assess the pre-development state of a site to calculate its biodiversity value. You must submit the Statutory Biodiversity Metric in Excel, with your application, to demonstrate how a minimum of 10% net gain will be delivered; we require on-site provision as the priority.
The Biodiversity Gain Plan needs to be prepared and submitted to the council. This will set out the strategy for achieving BNG, including all relevant information, habitat management plans and how the net gains will be managed and maintained.
Whilst on-site provision is the priority, if off-site BNG is accepted as a solution we will require a legal agreement that covers the use, maintenance and management of land for at least 30 years. Such land will be formally recorded on a Biodiversity Gain Register.